Thermal activation of fluorine for use in a semiconductor chamber

Abstract

A method and system for thermally activating a oxidizing cleaning gas for use in a semiconductor process chamber cleaning process. The oxidizing cleaning gas is thermally activated by reacting the oxidizing cleaning gas with heated inert gas. The resulting thermally activated oxidizing cleaning gas does not readily deactivate, thus providing enhanced cleaning capabilities.

What is claimed is:  
     
       1. A process for thermally activating an oxidizing cleaning gas comprising the steps of: 
       (a) reacting an oxidizing cleaning gas and a preheated inert gas to form a gaseous mixture having one or more radicals; and  
       (b) passing said gaseous mixture to a reaction chamber, wherein said one or more radicals react with one or more deposits contained within said reaction chamber to form a waste gas.  
     
     
       2. The process of  claim 1 , wherein said oxidizing cleaning gas is selected from the group consisting of: fluorine, chlorine, XeF 2 , ClFx, BrFx, O 2 , O 3 , NF 3 , fluorocarbon gas, and any combinations thereof. 
     
     
       3. The process of  claim 1 , wherein said oxidizing cleaning gas is flowed to said mixing chamber at a flow rate between about 1 slpm to about 20 slpm. 
     
     
       4. The process of  claim 1 , wherein said inert gas is selected from the group consisting of: argon, nitrogen, helium, and any mixtures thereof. 
     
     
       5. The process of  claim 1 , wherein said inert gas is flowed to said mixing chamber at a flow rate between about 1 slpm to about 20 slpm. 
     
     
       6. The process of  claim 1 , wherein said inert gas is preheated to a temperature between about 250° C. to about 800° C. 
     
     
       7. The process of  claim 1 , wherein said one or more deposits are selected from the group consisting of: silicon oxide, silicon nitride, polysilicon, tungsten silicide, titanium nitride, TaN, and any combinations thereof. 
     
     
       8. The process of  claim 1 , wherein said waste gas is at least one selected from the group consisting of: SiF 4 , CF 4 , WF 6 , TaF 5 , and TiF 4 . 
     
     
       9. A system for thermal activation of an oxidizing cleaning gas comprising: 
       (a) a mixing chamber which is capable of reacting an oxidizing cleaning gas and a preheated inert gas to form a gaseous mixture having one or more radicals; and  
       (b) a reaction chamber for use in semiconductor processing which is in gaseous communication with said mixing chamber, wherein said one or more radicals react with one or more deposits contained within said reaction chamber to form a waste gas.  
     
     
       10. The system of  claim 9 , wherein said oxidizing cleaning gas is selected from the group consisting of: fluorine, chlorine, XeF 2 , ClFx, BrFx, O 2 , O 3 , NF 3 , fluorocarbon gas, and any combinations thereof. 
     
     
       11. The system of  claim 9 , wherein said oxidizing cleaning gas is fed to said mixing chamber via a feed tube which has a diameter from between about ¼ inch to about 1 inch. 
     
     
       12. The system of  claim 9 , wherein said inert gas is selected from the group consisting of: argon, nitrogen, helium, and any mixtures thereof. 
     
     
       13. The system of  claim 9 , wherein said preheated inert gas is fed to said mixing chamber via an inert gas feed tube having a diameter from between ½ inch to about 2 inches. 
     
     
       14. The system of  claim 13 , wherein said inert gas feed tube comprises a packed bed of thermally conductive material. 
     
     
       15. The system of  claim 14 , wherein said thermally conductive material is a finely divided metal. 
     
     
       16. The system of  claim 15 , wherein said finely divided metal is selected from the group consisting of: nickel, Hastelloy, stainless steel, copper alloy, aluminum alloy, and any combinations thereof. 
     
     
       17. The system of  claim 13 , wherein said inert gas feed tube further comprises a heating means. 
     
     
       18. The system of  claim 17 , wherein said heating means surrounds said inert feed tube. 
     
     
       19. The system of  claim 17 , wherein said heating means is selected from the group consisting of: electrical resistance heaters, radiant heater, gas fired combustion heaters, and any combinations thereof. 
     
     
       20. The system of  claim 9 , wherein said reaction chamber is constructed from an inert material. 
     
     
       21. The system of  claim 20 , wherein said inert material is selected from the group consisting of: nickel, dense aluminum oxide, sapphire, aluminum fluoride, calcium fluoride, and any combinations thereof. 
     
     
       22. The system of  claim 9 , wherein said reaction chamber comprises an outer tube and a liner inserted inside the outer tube. 
     
     
       23. The system of  claim 22 , wherein said reaction chamber comprises a nickel outer tube and a sapphire liner. 
     
     
       24. The system of  claim 9 , wherein said waste gas is at least one selected from the group consisting of: SiF 4 , CF 4 , WF 6 , TaF 5 , and TiF 4 .